Expert on CSG warns of environmental and health impacts

Dr Stuart Khan, an environmental engineer and water quality expert from the University of New South Wales, made a submission yesterday to the NSW parliamentary inquiry outlining some of the major environmental and health impacts of coal seam gas activities.

Khan told the inquiry that national risk assessment guidelines should be set on the impact of drilling on aquifers, as poorly planned exploration and extraction activities can pose considerable risks to both groundwater and surface water systems.

Some of the key submissions points are:

• Drilling through aquifers, impervious rock and coal seams risks ‘interconnecting’ otherwise confined aquifers, which could lead to aquifers containing large volumes of pristine water becoming contaminated with toxic chemicals.
• Lowering of water levels in adjacent aquifers may affect water quality in those aquifers.
• Extracted CSG waters, which often contain toxic organic chemicals, present a significant risk to adjacent surface water and groundwater qualities.
• Reinjection of CSG wastewaters into other aquifers has the potential to contaminate those aquifers.
• Injection of fraccing fluids to coal seams, which contain chemical additives, may contaminate groundwater supplies. Furthermore, fraccing fluids are designed to alter the natural geochemical conditions and thus have the potential to mobilise other chemicals in aquifers.

Khan told the inquiry that regulators and policy makers in NSW are faced “with a severe lack of guidance, support, knowledge and experience for assessing and overseeing the safe management of CSG activities in this state.”

In addition to normal operations and CSG activities, Khan says the risk assessment guidelines should cover and require the following:

• Potential hazardous events that happen unexpectedly as a result of extreme weather, equipment failure or human errors and misjudgements. This could be a leak or a spill or the unintended fracturing of an aquifer.
• More comprehensive characterisation of the complex chemical mixtures in CSG water to gain a better understanding of the human health risks.
• Water quality monitoring well before CSG activities begin, which adhere to the Australian and New Zealand Guidelines for Fresh and Marine Water Quality and the Australian Drinking Water Guidelines (National Water Quality Management Strategy. “Background” monitoring is needed so results of later monitoring can be effectively interpreted and the impacts of CSG activity properly gauged.

There are a number of listed recommendations in Dr Khan's complete submission document.  He is available for comments and can be reached on first instance by email at s.khan@unsw.edu.au.